Back-kest for lathes



UNITED sTATEs PATENT oEEioE.

WM. H. HENDRIGK AND JOS. JACOBS, OF MOUNT VERNON, OHIO.

BACK-REST FOR LATHES.

Speccation of Letters Patent No. 26,988, dated January 31, 1860.

To all whom it may concern.'

Be it known that we, VILLIAM H. HEN- Dmcx and J JACOBS, both of MountVernon, in the county of Knox and State of Ohio, have invented a new,and Improved Back- Rest or Stay for Turning Lathes; and we do herebydeclare that the following, is a full, clear, and exact description ofthe same, reference being had to the annexed drawings making a part ofthis specification, in which- Figure l, is a front view of ourinvention, the socket in which it is secured being bisected transverselyas indicated by the line Fig. 2. Fig. 2, is a side View of ditto.

Similar letters of reference indicate corresponding parts in the twofigures.

The object of this invention is to obtain a simple and more eficientdevice than has hitherto been employed for supporting work, while beingturned so as to prevent any tremor of the same and efl'ectually resist,the pressure of the tool on the work, thereby insuring the even or trueturning thereof.

The invention consists, in having two or more rollers, placed in acurved arm or bar, and so disposed or arranged as to form a bearing forthe work the lower end of the arm or bar being secured by a bolt in asocket, and tted loosely on the bolt so that the device may be readilyadjusted to and from the work as may be required, and secured in properposition to the work by a set-screw.

To enable those skilled in the art, to fully understand and constructour invention we will proceed to describe it.

A represents an oblong rectangular box, or socket, in which the lowerpart of a curved arm of bar B, is secured by a bolt a, the arm or barbeing allowed to turnfreely on the bolt cz. The upper portion of the armor bar is the curved part, and said curved portion is of semicircularform as shown clearly in Fig. 2. This curved portion of the arm or bar,is slotted vertically so as to form a recess or chamber to receiverollers C, which may be of equal diameter the peripheries of whichrollers project beyond the concave edge of the arm or bar as shownclearly in Fig. 2. The rollers C, are fitted on shafts Z), which passthrough oblong slots o, in the arm or bar, the slots having such aposition relatively with each other, as to admit of the rollers beingadjusted nearer to or farther from a point which is the center of acircle of which the curved portion of the arm or bar is a part, andconsequently it will be seen that the oblong slots c are placed inradial lines, from said point. The shafts b, of the rollers C, aresecured in any part of the slots, c, by thumb nuts d, which are fittedon screw threads at one end of the shafts Z), the opposite ends havingheads e, on them.

Through one side of the box or socket A a set screw D passes. The innerend of this screw bears against the lower part of the arm or bar B, justabove the bolt a, and a small hole may be made in the arm or bar toreceive the inner end of the set screw D.

All the parts abovedescribed may be of metal, and the box or socket maybe secured transversely, to the bed of the turninflr lathe, by anyproper means. The work after being centered in the lathe and turned atabout its center to a cylindrical or approximate form has the rollers-C,fitted to it, one roller being above, one below, and the other at theback of the work, see Fig. 2, in which the work is shown in red. Theserollers are adjusted so as to fit snugly to the work by loosening thethumb nuts d. The work is allowed to turn freely within the recess orbearing surfaces, formed by the rollers C, while the latter willperfectly sustain the work without marring it, and prevent all tremor ofthe same, and etectually resist, the pressure of the tool applied to it.After the work is first roughed-off, a perfect cylindrical portion maybe turned for the rollers C, to bear against in order that the lattermay serve as a perfect stay and insure the even or true turning of thework. When the work is completed, the arm or bar B, is thrown backwardfrom the work, the setscrew D, being loosened, and the finished work isremoved from the lathe, and another piece adjusted in it, to be operatedupon and supported as before.

In turning ong work of small diameter a bearing or support is essential.

Hitherto so far as we are aware a simple prop or stay has only been usedbearing directly against the Work and causing considerable friction. Webelieve that antifriction supports or bearings have been used onautomatic lathes, or those in which the cutting tools, are moved by amechanism operating eonjointly with the other working partsl of thelathe, but such supports or bearings have been arranged quitedifferently from ours, and were not capable of being applied to anordinary turning lathe.

It would be preferable to have three rollers C, as they would form aperfect bearing; two rollers however might be used.

We do not claim broadly the employment or use of a back-rest or stay forturning lathes, irrespective of the construction, and

arrangement herein shown and described,

but

We do claim as new, and desire to secure by Letters Patent, 15

The curved arm or bar B provided with two or more adjustable rollers C,and secured at its lower part in a boX or socket, A, substantially asand for the purpose set forth.

WM. H. HENDRICK. JOSEPH JACOBS.

Witnesses:

T. V. PARKE, W. M. CLELLAND.

